I was wondering if there are any open source game servers built on planeshift that are functional?

Purpose: to setup a game server for my kids and their friends at school.  I have no interest in having a 9 year old connect to a public server with anyone on it, but setting up my own server for them to play on and letting them invite others is fine[as then it grows within their age group)

I understand that I can't do that with Planeshift the game, but I figure there might be a game based off the engine out there.